1996 yukon ..new brakes etc.....no brakes

[roonie]

bought this 1996 4x4...5.7 auto yukon and it had a rather soft and low pedal. Ive changed litterally every brake part imaginable and had the whole system bleed by a shop and still no brakes. Parts changed include....master cylinder.....pads,shoes......new drums (not turned old ones). In fact the only item i have not changed would be the wheel cylinders because they were not leaking. Anyone have a clue for me? Could the ABS cause this. thanks

[jdl]

I'd check for abs codes. That shop couldn't fix it??

[FishFind]

did someone bench bleed the master cyl before it was put in??

They are symptoms of low fluid, bad master cyl or a leak somewhere that allows your brake fluid to drain out when you step on the brake.

If you pump the brakes can you get it to build up pressure

[roonie]

Originally Posted by FishFind

did someone bench bleed the master cyl before it was put in??

They are symptoms of low fluid, bad master cyl or a leak somewhere that allows your brake fluid to drain out when you step on the brake.

If you pump the brakes can you get it to build up pressure

the master cyl. was changed by a very qualified competent mechanic. There are no leaks anywhere in the system. The pedal is almost to the floor. It only comes up slightly when pumped.
There are parts in a box that we found of an old master cly and the truck had the master cyl changed at one time as there is used auto part markings on it. The last owner is/was mexican so very hard to talk to due to language bariers. Anyway...this master cyl is brand new, not remanufactured.

[roonie]

Originally Posted by jdl

I'd check for abs codes. That shop couldn't fix it??

there comes a time when you throw hundreds of dollars at a shop to fix the brakes, that you have to walk away. lol My bro has a code reader so i guess thats next.

[FishFind]

Well this is beyond me. I hope that someone with a little more know how on the matter will come along and help you out here.

I know it may sound stupid but did you flush the brake fluid out?? Maybe the guy before put power steering fluid or something else in by accident?

[roonie]

yeah its way beyond us too. My father is a former stock car racer etc. so he knows his stuff. What i really love about this kinda mystery is when the truth is finally surfaced. We are going to read the codes next. The only other thing i can think is this suv showed a different type of master cyl. listed for diesel engines but some also had the different type of master cyl. for non diesel engines. Maybe the last guy put the wrong one on from the get go. Will keep you posted. the old fluid has been pushed out........all new fluid.

[maxwedge]

The design of the m/c is not part of the abs diagnosis, post the codes when you get them.